I am sad because of the girl I like

I am bisexual and so is the girl I’m talking to. We both have wanted to kiss each other for a while and we hold hands now and cuddle and stuff. It’s getting kind of more exclusive/serious but I have one problem. Any time I hangout with her she just goes on her phone and doesn’t pay a lot of attention to me. Also last night she was snapchatting this guy she claims she “doesn’t like” but he likes her and I know she’s interested in him. I just don’t know what to do about the situation